| English noun: blackjack | 
| 1. | blackjack (plant) a common scrubby deciduous tree of central and southeastern United States having dark bark and broad three-lobed (club-shaped) leaves; tends to form dense thickets | 
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 | Synonyms | blackjack oak, jack oak, Quercus marilandica | 
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 | Broader (hypernym) | scrub oak | 
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| 2. | blackjack (artifact) a piece of metal covered by leather with a flexible handle; used for hitting people | 
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 | Synonyms | cosh, sap | 
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 | Broader (hypernym) | bludgeon | 
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| 3. | blackjack (artifact) a flag usually bearing a white skull and crossbones on a black background; indicates a pirate ship | 
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 | Synonyms | black flag, Jolly Roger, pirate flag | 
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 | Broader (hypernym) | flag | 
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 | Part holonym | skull and crossbones | 
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| 4. | blackjack (act) a gambling game using cards; the object is to hold cards having a higher count than those dealt to the banker up to but not exceeding 21 | 
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 | Synonyms | twenty-one, vingt-et-un | 
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 | Broader (hypernym) | card game, cards | 
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